The mobile communication system has been developed for the user to communicate on the move. With the rapid advance of technologies, the mobile communication system has evolved to the level capable of providing high speed data communication services as well as a voice telephony service.
Recently, standardization for a long-term evolution (LTE) system, as one of the next-generation mobile communication systems, has been underway in the 3rd generation partnership project (3GPP). LTE is a technology for realizing high-speed packet-based communications at a data rate of up to 100 Mbps, which is higher than the currently available data rate, and its standardization is almost complete.
For improving data rates, recent studies are focused on LTE-Advanced (LTE-A) with the adoption of various new techniques to the legacy LTE system. One of such technologies is Carrier Aggregation. Unlike the conventional technology of using one downlink carrier and one uplink carrier for data communication, Carrier Aggregation is a technology allowing a terminal to use multiple downlink carriers and multiple uplink carriers.
In the case where multiple base stations transmit data over aggregated frequency resources, however, inter-base station latencies may cause data transmission resource waste.